Activation of Small Molecules Mediated by Photoredox reactions of Metal Complexes
| Project/Area Number |
63550609
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
工業物理化学
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| Research Institution | Kyushu University |
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Principal Investigator |
MATSUDA Yoshihisa Kyushu Univ., Dept. Organic Synthesis, Associate Professor, 工学部, 助教授 (10037757)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Porphyrin complexes / Early transition metals / Oxidation of phenols / Photoredox chemistry / 光化学的活性化 / 前半遷移金属 / 小分子の光活性化 / エポキシ化 |
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| Research Abstract |
Tri-mu-oxobis(tetraphenylporphinatoniobium(V)), complex 1, was prepared. Coordination behaviors of alcohols, phenols and nitrogen bases at the axial sites of 1 were followed by means of visible absorption spectroscopy. Alcohols and phenols coordinated to 1 at the axial site and resulted mononuclear complexes, [Nb(tpp)(O)(L)(HL)], 2. Catechol acted as a bidentate ligand and afforded a complex, [Nb(tpp)(O)(Hcat)], 3.2,6-di-t-butylphenol and nitrogen bases did not coordinate to 1.
The complex 1 in benzene was reduced upon anaerobic irradiation with visible light in the presence of monodentate ligands such as alcohols or phenols. Aerobic irradiation of 1 gave superoxide complexes in the presence of phenols, while no such complexes were detected upon aerobic irradiation in the presence of alcohols. The complex 3 did not react upon irradiation under the both aerobic and anaerobic conditions. The complex 1 in benzene without addition of ligands gave a superoxide complex upon aerobic irradiation, but it was not reduced upon anaerobic irradiation conditions.
A benzene solution of 1 showed a time resolved ESR signal due to a triplet biradical after pulsed irradiation under anaerobic conditions. The triplet species activated the coexisting molecular oxygen under aerobic conditions. The complex 2 gave corresponding phenoxyl radical upon anaerobic pulsed irradiation. The Additives which did not coordinated to 1 did not give transient radical species upon anaerobic irradiation. The activation of the additives coordinating to 1 was initiated by homolysis of the axial coordination bond.
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Report
(3 results)
Research Products
(12 results)
